Turbine engines make use of turbine blades which are attached to the rotating shaft of the turbine. Hot combustion gases passing through the turbine section of a turbine engine impinge upon the turbine blades, which causes the blades and the attached shaft to rotate. Typically, a turbine engine will include multiple rows of blades mounted on the rotating shaft, as well as multiple rows of stationary blades. The rows of rotating and stationary blades alternate with one another.
Hot combustion gases which have passed by a row of rotating turbine blades then impinge upon the following row of stationary blades. The row of stationary blades re-direct the combustion gases before they arrive at the next row of the rotating turbine blades.
Both the rotating turbine blades and the stationary blades are subjected to an extremely harsh operating environment. The blades experience high temperatures, and the passage of extremely hot combustion gases at high velocities. To help the rotating and non-rotating blades within the turbine section cope with the harsh operating environment, it is common to form cooling passages within the blades themselves. The cooling passages are supplied with a coolant, typically in the form of cooled compressed air. The compressed air moves through the cooling passages within the blades to help cool the blades, and the coolant usually then exits the blades through multiple cooling holes formed on the exterior surface of the blades.